$laws of reflection and refraction$ $laws of reflection and refraction$

Let’s understand how Huygens’ Principle can help us prove the laws of refraction with the help of the above diagram.Ĭonsidering a wavefront BC incident on the surface, we evaluate that the incident ray has a velocity of V 1 and the refracted ray AD has a velocity of V 2. This phenomenon of the bending of light is called the refraction of light.

$laws of reflection and refraction$

The velocity of light is changed when the light wave passes from one medium to another. Huygens’ Principle and Laws of Refraction

$laws of reflection and refraction$

Therefore, both the laws of reflection can be analysed through Huygens’ Principle. The normal, incident ray, and reflected ray lie on the same plane, and hence, the second law of reflection is proven. The normal is perpendicular to the reflecting surface and originates at the point of incidence. It is also observed that the incident ray and the reflected ray lie on opposite sides of the normal. The direction of propagation of the secondary wavelets is also the direction of propagation of their primary wave sources. Therefore, the angle of incidence will be equal to the angle of reflection. As mentioned by Huygens’ principle, the rays will take equal time to cover the distance between A to D and C to B. Every point on aA acts as a source of a secondary wavelet. The above figure demonstrates the incident ray being reflected by a reflecting surface.ĪA represents the wavefront incident in a reflecting mirror XY with an angle of incidence i. Huygens’ Principle can be applied to prove the laws of reflection. Huygens’ Principle and Laws of Reflection For a differing medium, the density may cause a change in velocity and distance, but time will remain the same.Īll the points on a particular wavefront act like another source of spherical waves called secondary wavelets. The time taken by a wave to travel from one wavefront to another will always remain constant. The important considerations of Huygens’ Principle are:Īll the rays, i.e., the tangents, are always perpendicular to the primary wavefront. It also mentions how at any instant of time, a tangent on any of the wavelets can give rise to a new wavefront. It further elaborates on the movement of these wavelets, highlighting that they spread in all directions exactly like the primary source wave. Huygens’ Principle states that every point on a wavefront is the source of wavelets that spread out in the forward direction at the same speed as the wave itself. This principle is also called the Huygens-Fresnel Principle.

$laws of reflection and refraction$

The resultant wave obtained from these spherical waves is the sum of all spherical waves. This allows the waves to move freely and contributes to the peculiar behaviour of each wave. He suggested that every point on the wavefront of a wave acts as a source of a wave that is spherical in nature. This movement is supported by defining characteristics possessed by waves, one of which was highlighted by Huygens in 1678. Therefore, Huygens’ principle comes in extremely handy when trying to understand their behaviour regardless of the medium they are travelling in. Electromagnetic waves can often be unpredictable and not adhere to the principles of their behaviour. This principle helps not only in understanding the movement of waves, but also in describing them. Huygens’ Principle is of extreme importance when studying waves and analysing them.

$laws of reflection and refraction$

Laws of reflection and refraction